NXP TJA1051T/112 High-Speed CAN Transceiver: Datasheet, Application Circuit, and Key Features

The NXP TJA1051T/112 is a widely-used high-speed Controller Area Network (CAN) transceiver that serves as the interface between a CAN protocol controller and the physical two-wire CAN bus. Complying with the ISO 11898-2 and ISO 11898-5 standards, it is designed for high-speed automotive and industrial applications requiring data rates up to 1 Mbaud.

Key Features

A primary strength of the TJA1051T/112 is its excellent ElectroMagnetic Compatibility (EMC) performance. It features a very low electromagnetic emission and high electromagnetic immunity, which is critical for operation in the harsh electrical environments of vehicles. The device also includes advanced protection and safety features such as:

High ESD (ElectroStatic Discharge) protection: ±8 kV on the bus pins (IEC 61000-4-2), safeguarding the component from static damage during handling and operation.

Undervoltage detection on the VCC supply pin.

Thermal protection that disables the transmitter if the junction temperature becomes excessive.

A dominant time-out function that prevents the bus lines from being driven permanently dominant, a common failure mode.

Furthermore, it offers a low-power management mode with very low quiescent current, making it ideal for power-sensitive applications like battery-powered nodes or automotive sleep/wake-up systems.

Application Circuit

The typical application circuit for the TJA1051T/112 is straightforward, facilitating easy integration into a CAN node. The core connection involves:

1. Microcontroller/Controller Interface: The TXD (Transmit Data Input) and RXD (Receive Data Output) pins connect directly to the corresponding pins of a CAN controller (often integrated within a microcontroller).

2. Power Supply: A 5V ±4% supply (VCC) is required, typically decoupled with a 100 nF capacitor close to the pin.

3. CAN Bus Connection: The CANH (CAN High) and CANL (CAN Low) outputs are connected to the physical CAN bus. A common-mode choke and series resistors are often added in series with these lines to further enhance EMC performance.

4. Termination Resistors: A 120-ohm termination resistor must be placed between CANH and CANL at each end of the CAN bus to prevent signal reflections.

Datasheet Insights

The official datasheet is the ultimate source for design-in. It provides critical details such as:

Absolute Maximum Ratings: The operational boundaries for supply voltage, bus pin voltages, and storage temperature.

DC and AC Electrical Characteristics: Detailed specifications for bus levels, receiver thresholds, timing parameters (e.g., loop delay), and current consumption in all modes.

Truth Table: Explains the behavior of the device based on the states of the S (Standby/Sleep mode control) and TXD pins.

Package Information (SO8): Outlines the mechanical dimensions and pinout for the 8-pin Small Outline package.

ICGOOODFIND

The NXP TJA1051T/112 stands out as a robust, reliable, and industry-proven solution for implementing CAN node interfaces. Its superior EMC characteristics, integrated fault protection, and low-power capabilities make it a premier choice for designers tackling demanding automotive and industrial network challenges.

Keywords

1. High-Speed CAN Transceiver

2. ISO 11898-2

3. ElectroMagnetic Compatibility (EMC)

4. Low-Power Mode

5. ESD Protection